The invention relates to an illuminated decorative part.
Illuminated decorative parts, in particular for adjustable ambient lighting within a vehicle, are known from the prior art. Patent DE 10 2009 030 684 A1 by the applicant relates to a decorative element of this type, which has a transparent top layer, into which light can be coupled. Corresponding cut-outs can then be provided in an applied decorative film in order to emit the light through them, in particular into the interior compartment of a vehicle that is equipped with the decorative element.
An illuminated decorative part of the type in question is known by the term ‘decorative lighting unit’ from DE 10 2010 055 129 A1. The decorative lighting unit consists of a support that is provided with light sources, an optical element in the form of an optical lens, and a diffusor and a mask. A stripe image or another type of image display is inserted between the diffusor and the lens and is then projected by the light sources onto the illuminated surface of the decorative part. The design of the decorative lighting unit in the generic prior art has the disadvantage that, due to the lens and the inserted stripe image in the interior of the decorative lighting part, it requires a relatively large design in the direction of the light emission, i.e. substantially orthogonally to the surface facing the observer of the decorative lighting part. This is disadvantageous for use, for example, in the area of a dashboard of a motor vehicle, since the available installation space here is typically very limited in the depth direction. A further disadvantage consists in the fact that a stripe image is required in order to represent the desired display. Typically, this stripe image is transilluminated in the manner of a transparent photo slide, which leads to a not insignificant loss of light, and which correspondingly limits the optical brilliance that can be achieved with the decorative lighting unit according to the generic prior art.
The problem addressed by the present invention thus involves an illuminated decorative part that can be constructed to be very compact, especially in its overall height in the direction in which the light is emitted, and that nevertheless permits a very brilliant and high-contrast emission of light.
Similar to the generic prior art, the illuminated decorative part according to the invention has optical elements between a flat visible side and an illumination region that is behind the visible side as viewed by the observer. The optical elements in the form of at least one flat scattering element are arranged between the visible side and the illumination region in order to distribute the light from the light sources evenly over the surface of the visible side in the region in which it illuminates the optical scattering element over a distance. The necessary distance between the light sources and the flat scattering element creates an even scattering so that individual light sources can no longer be discretely recognized from the visible side. A volume scattering element, especially one consisting of PMMA, such as df23, with the material known as 0v200, which is marketed under the brand name “Plexiglas,” is suitable as a flat scattering element, for example.
According to the invention, it is additionally provided that light guides for guiding the light orthogonally to the surface of the visible side are arranged between the scattering element and at least one—but not all—of the light sources. These light guides, which are arranged between the scattering element and one or more of the light sources in the form of stripes or other geometric patterns, for example, then transfer the light from the light source directly either into a suitably shaped cut-out in the scattering element or, preferentially, in a scattering element that is arranged over the entire surface, onto it. In the preferred embodiment, there is no distance from light guide to the scattering element. Moreover, the distance between the light guide and the light source is much smaller than the distance between the adjacent light sources, which are not connected to the light guide, and the scattering element. In this way, different light intensities are permitted in the region of the scattering element, and so, using strip-like light guides on the surface of the scattering element strip, for example, it is possible to produce stripes with very high light intensity and directed light as well as regions between them with lower light intensity and scattered light.
The light guides according to the invention are not configured to be scattering themselves, but are instead clear in order to permit the best possible transmission of the light into the region of the flat scattering element or into the region of the visible side and/or the decorative layer arranged there.
According to a very advantageous development of the concept, it is possible that the scattering element serves as a support for a decorative layer, which is configured to be entirely or at least partially transparent. A decorative layer such as this can ideally be sprayed onto the scattering element. For example, it can consist of a sufficiently ductile material to ensure crash safety for use in a vehicle despite the use of the optically very high-grade PMMA, which alone would not provide any crash safety. At the same time, the design becomes extraordinarily simple and efficient, since very direct backlighting of the decoration and thus very brilliant light emission into the environment of the illuminated decorative part is possible as a result of the direct connection between the scattering element and the preferentially transparent decorative layer.
In a very advantageous development, it is furthermore possible that the light guides have a non-transparent mask over at least part, preferably all, of the surface on their edges that run perpendicular to the surface of the visible side. The mask can be configured as a lateral sheath on the light guide, for example. Scattered light, which could otherwise exit the light guides transversely to the actual direction of the light transmission, is minimized as a result. The brilliance of the regions of the visible side that are in connection with the light guides compared to the other regions is increased even further, and so an even better contrast of the image generated by the illuminated decorative part becomes possible.
In one advantageous development, the decorative layer can be configured in the optical form of tinted glass, for example. The transparency of the decorative layer is thereby deliberately reduced so that it is translucent only when the light sources are switched on, while it is not translucent when the light sources are switched off. In this way, the elements of the illuminated decorative part can be prevented from being recognized in the deactivated state, which is an advantage with regard to the design in the deactivated state, which is often also called the cold design.
Additionally, or in particular alternatively, it is also possible that a semi-transparent intermediate layer is arranged between the decorative layer and the optical elements, and especially in this case the scattering element that is ideally configured over the entire surface. It is also possible to impede the view of the rear-side elements of the illuminated decorative part using this type of semi-transparent intermediate layer, regardless of the transparent design of the decorative layer, so that a very uniform appearance without translucent functional elements is created in the deactivated state. Especially in the automotive industry, this is also described with the term “black panel design” or “black panel effect.”
The semi-transparent intermediate layer can be configured preferably as a film, which is applied to the full-surface scattering element, for example, before the actual decorative layer, in this case the applied film, is sprayed onto it.
According to a further very favorable embodiment of the illuminated decorative part according to the invention, the light sources are configured in the form of a field of light-emitting diodes on a support element. This kind of field and/or a matrix of light-emitting diodes is very simple to produce. The support element itself in this instance can ideally be black in order to further reduce the chance of shining through the transparent visible-side elements. The light-emitting diodes themselves offer the advantage that they can be constructed very compactly with respect to the installation space in the direction in which they emit the light. Moreover, they require less energy, and so the heating of the illuminated decorative part stays within limits when light-emitting diodes are used as a light source, which offers a crucial advantage especially when they are installed in confined spaces, such as within a dashboard of a vehicle. Furthermore, the light-emitting diodes can be activated very easily and efficiently. In particular, various desired colors can be represented due to the combination of multiple light-emitting diodes into one single light source. In this way, the desired levels of brightness, colors, color gradients, moving color changes, chases or the like can easily and efficiently be set in the illuminated decorative part by means of simple control electronics. All of this is generally known from the activation of light-emitting diodes, and so it is not necessary to go into further detail at this point.
As has already been mentioned, the illuminated decorative part according to the invention can be constructed extraordinarily compactly, especially in the direction in which the light is emitted toward the observer onto the visible side. It is an extraordinarily simple design, in which, in particular, the scattering element serves as one of the supporting elements and can, for example, be mechanically clipped to support elements that accommodate the light-emitting diodes as light sources. This design as a whole is very flat. By means of the light guide elements between the individual light sources and/or light-emitting diodes and the scattering element, effects such as stripes or the like can be represented very efficiently and brightly. The optical quality of the illuminated decorative part is thus accordingly light. At the same time, a tinted glass appearance or the use of semi-transparent intermediate layers can achieve a design in which a very homogeneous and thus high-quality appearance of the decorative part is achieved when in the deactivated, i.e., not illuminated, state.
In principal, the illuminated decorative part according to the invention can be used in all industries. Its especially preferred use, however, is in the field of the interior design of vehicles. It can be ideally employed here for illuminated design elements and the so-called ambient interior lighting of the vehicle. It is simple and easy to construct and, as has been discussed above, can be implemented with a high degree of crash safety, especially by the use of suitable materials, even when visually high-quality materials, such as PMMA, are utilized. In particular, the semi-transparent intermediate layer can be configured in the form of a polycarbonate film, which further increases crash safety.
Further advantageous embodiments of the illuminated decorative part according to the invention as well as its use can also be found in the exemplary embodiment, which will be discussed in greater detail below with reference to the figures.